* Earlier reports said up to four assailants involved in attack
* China increasingly nervous about Islamic militancy
* TV pictures show suspect pressed to ground (Adds senior official's comments on fighting terror)
By Ben Blanchard
BEIJING, May 6 (Reuters) - An assailant stabbed six people on Tuesday at a railway station in the southern Chinese city of Guangzhou, police and state media said, the latest in a series of attacks that have unnerved the country, some of which Beijing has termed terrorism.
Police gave no reason for the attack, but China has grown increasingly nervous about Islamic militancy since a car burst into flames on the edge of Beijing's Tiananmen Square in October and 29 people were stabbed to death in March in the southwestern city of Kunming.
The government blamed militants from the restive far western region of Xinjiang for both those attacks. Xinjiang, a resource-rich and strategically located region on the borders of central Asia, has for years been beset by violence blamed by the Chinese government on Islamist militants.
Despite earlier reports on state media that up to four assailants may have been involved in the latest attack, Guangzhou police said their initial inquiry found there was just a single suspect. He had been shot and wounded.
"After verbal warnings were ineffective, police fired, hitting one male suspect holding a knife, and subdued him," Guangzhou police said on their official microblog.
They neither identified the attacker nor gave a possible motive.
Xinhua news agency said that the attacker had been hospitalised, and that police were not immediately able to identify him as he had no documents on him.
State television said that reports police had picked up another suspect near the station were also wrong, and that a person who had been detained had nothing to do with the case.
Provincial television showed pictures of what it said was an apparently injured suspect being pressed to the ground by police and plainclothes security officials, as they removed a bloodied white t-shirt. It was not possible to see the person's face.
Speaking while on a visit to Hong Kong, U.S. Assistant Secretary of State for East Asian and Pacific Affairs Daniel Russel expressed "horror, outrage and sympathy" at the attack.
"We oppose terrorism in all forms, and in those instances where the available information or the information shared by the Chinese authorities pointed to terrorism by a group or individual, we have condemned it as terrorism," he said.
China last week reacted angrily to U.S. criticism of the level of cooperation from Beijing on fighting terrorism.
China blamed religious extremists for a bomb and knife attack last Wednesday at a train station in Urumqi, the regional capital of Xinjiang, that killed one bystander and wounded 79.
The government called the attackers "terrorists", a term it uses to describe Islamist militants and separatists in Xinjiang who have waged a sometimes violent campaign for an independent East Turkestan state.
Exiles and rights groups say the real cause of the unrest in Xinjiang is China's heavy-handed policies, including curbs on Islam and the culture and language of the Muslim Uighur people.
China's domestic security chief, Meng Jianzhu, told a meeting of Chinese law enforcement officials on Tuesday that the government would launch "special operations against terrorism", Xinhua reported.
Meng said that the authorities would hit terrorists hard and "deploy new technologies to detect and remove security threats", Xinhua said, without elaborating. (Additional reporting by Li Hui and Michael Martina, and Greg Torode in HONG KONG; Editing by Nick Macfie)